Means for effecting calibration of the tire inflator spring of tire inflating apparatus



MEANS FOR EFFECTINC CALIBRATION OF THE TIRE INFLATOR SPRING OF TIRE INFLATING APPARATUS Filed Oct. 29, 1947 3 Sheets-Sheet l o v 0 X fio - A a 13 A L2 Feb. 12, 1952 D. s. wlLLsom MEANS FOR EFF 2,585,362 ECTING CALIBRATION OF THE TIRE INFLATOR SPRING OF TIRE INFLATING APPARATUS Filed Oct, 29, 1947 5 Sheets-Sheet 2 ui l i W v I INVENTOR: id SW on,

ATTORNEY.

Feb. 12, 1952 D. MEANS FOR EFFECTIN INFLATOR SPRING 0F Filed Oct. 29. 1947 S. WILLSON G CALIBRATION OF THE TIRE TIRE INFLATING APPARATUS 3 Sheets-Sheet 3 INVENTOR:

A TTORN Patented Feb. 12, 1952 MEANS FOR EFFECTING CALIBRATION OF THE TIRE INFLATOR SPRING OF TIRE INFLATING APPARATUS David- SQWillson, Muskegon Heights, Mich assignor to John Wood Manufacturing Company, Inc., Philadelphia, Pa, a corporation of Dela- Ware Applicationoetober 29, 1947, Serial No. 782,810

4 Claims.

for effecting calibration of the infiator spring of tire inflating apparatus which is-adaptable for charging an air receiver to a predetermined pressure. My invention is particularly adaptable for use, for example, intire inflating apparatus of the type disclosed in my co-pending application Serial No. 639,674 filed November 24, 1945, by Josephv C-. Wood-ford and myself for Improvement in Fluid Dispensing Apparatus; the type of apparatus disclosed Letters Patent of the United States No. 2,162,474 granted June 13,1939, to Virgil D. Barker; etc.

My invention may be embodied with particular advantage in apparatus used in automobile serv-- ice stations for inflating the tiresof motor vehicles to a predetermined pressure. It is ordinary practice in service stations tohighly compress air; say from 100 to 150 pounds per square inch, by a compressor operated by an electric motor, and to store such highly compressed air in a supply tank from which it may be released through tire inflating dispensing apparatus which is adjustable to predetermine the pressure to which anyair receiver may be charged.

During assembling of the apparatus, the apparatus is calibrated so that it will automatically inflate tires accurately to the pressure for which the. apparatus is set selectively by the operator.

The pressure setting is indicated visibly on a series of number wheels having on their circumferences a series of numbers from 1 to 9 inclusive and zero; or is indicated visibly on a flat dial by a pointer hand; etc.

Calibration ofthe apparatus is effected by adjustment of the efiective length of the main inflating. spring one end. of. which is operatively connected to the main lever of. the apparatus. As said main. inflating springs are manufactured in. quantity production, there may be slight variations in. the effective stresses of. the springsfor a given length of. spring. Hence, it is highly desirable that means he provided in. the apparatus by which the required adjustment of the efiecti-ve length of the spring may be made facilely in. calibrating of. the apparatus.

One feature of my invention. is that minute adjustments of the effective length of the main inflating spring may be made, which permits of greater accuracy of the apparatus.

Another feature of my invention is that adjustments of. the effective length of the main inflating spring may be made more facilely.

Another feature of my invention is that means are provided to maintain the outer adjusting.

member in non-rotatable position in the casing of the apparatus, with the cooperating inner nut selectively rotatable through any number of degrees of rotation as may be necessary to effect the required adjustment. Y

My invention includes the various novel features of construction and arrangement hereinafter more definitely specified.

In said drawings; Fig. 1 is an elevation of my invention as embodied in a tire inflating apparatus, but with the cover of the apparatus omitted.

Fig. 2 is an elevation ofthe opposite side of the apparatus shown in Fig. 1.

Fig. 3 is a plan view, partly in sectionyof the infiator spring assembly. I

Fig. 4 is a left-hand end elevation ofthe" structure shown in Fig. 3.

Fig. 5 is an elevation, onan" enlarged scale, of the adjusting nut indicated in Fig. 3'.

Fig. 6' is a fragmentary elevation of the portion of the casing in which the infiator spring assembly is mounted in cooperative relationship.

Fig. 7 is a fragmentary vertical sectional'view of the casing shown in Fig. 6-, taken on the lines T in Fig. 6. 1

A full and detailed description of the general operation of the tire inflating apparatus herein shown is setforth' in my said co pen'ding application Serial No. 630,674. My present invention relates only to means for calibrating the infiator spring of such a type of apparatus-,- and my present invention may be understood fully without including herein a detailed descriptionof the operation of the tire inflating mechanism per se which forms no part of my present invention.

Referring to said drawings, the reference mark I indicates the outer casing of an inflating apparatus which is adaptable for charging an air receiver, such as an automobile tire, to a predetermined pressure. The apparatus indicated is of the type which operates over a wide range of pressure adjustments, and operates in controlled cycles of pulsating charges of air to the receiver, each charge of air beingt'erminate'd at a short interval after it is initiated. Said casing I has a bottom wall 2 attached thereto by means of screws 3. Flexible diaphragms 4 and 5 are clamped between said bottom wall 2 and the diaphragm cover plate I by means of a series of screws 9 which extend through openings" in the periphery of the cover I and di'aphragins 4 and 5 into screw threaded openings in the bottom wall 2. Said diaphragms 4 and 5' form fluid tight seals around the peripheries of' the' diaphragm chambers formedin said cover plate 1.

A supply source of air under high pressure is connected by suitable piping to the inlet fitting ||I of the strainer H of the apparatus. The supply cf air under high pressure. after passing through the strainer I, is connected to the valve casing |2 through the inlet conduit l3 and inlet conduit fitting H. The conduit l5 connects the valve casing 12 with the fitting IS, the righthand side of which is adapted to be connected with a fluid service conduit of the well known construction which has at the distal end thereof an air valve chuck for attachment to the valve stem of an automobile tire. Such air chucks are well known in the art and include a valve which closes to prevent air escaping from the hose when the chuck is not attached to a tire stem, but which valve is opened and automatically unseats the tire valve when the chuck is applied to the tire valve stem. The fitting I6 is provided with a passageway in communication with the inflator diaphragm chamber.

The inflator diaphragm 5 is provided with a diaphragm plunger which rests upon the upper surface of the diaphragm 5, and said plunger has an upwardly extending stem which is in cooperative relation with the short arm of the bell crank main inflator lever 2|! which is pivotally mounted on the fulcrum pin 2|.

As best shown in Fig. i, the inflator spring 25 is operatively connected at its right-hand end to the upper end of the main lever 20.

As best shown in Figs. 5 and 3, the inflator spring adjusting nut member 26 is provided at itsright-hand end portion with an external screw thread 2'! which is adapted to be screwed into the nut-like opening of the spring 25. With the spring 25 not under stress, the convolutions of the spring 25 form a nut-like internal opening therein, and the pitch diameter and form of the screw thread 2! is such that the right-hand end of the member 26 may be screwed into the spring 25. The member 26 is provided, conveniently,

with an intermediate reduced diameter portion 30, and enlarged diameter portion 3| at its lefthand end, as viewed in Fig. 5. Said enlarged diameter ortion 3| is provided with an external annular groove 32, and said enlarged diameter portion 3| is adapted to be engaged in the an nular recess 34 formed at the right-hand portion of the outer locking ring member 35.

The ring member 35 is provided with the radial screw threaded openings 31 therethrough for set screws 39 adapted to be seated in looking engagement in the groove 32 to prevent relative turning movement between the ring member 35 and the infiator spring adjusting nut member 25 after the member 26 has been screwed into proper position in the spring 25. The ring member 35 has the external lug 40 adapted to be slidably engaged in the recess 4| of the offset portion42 formed in the middle wall 43 of the casing After the set screws 39 have been seated in the groove 32, the lug 40 engaged in the recess 4| prevents rotation of the ring member 35, member 26, and spring 25 to assure that the stresses of the spring 25 remain constanmas calibrated.

The inflator spring adjusting nut member 26 is provided with the axial screw threaded opening 41 therethrough which is in-screw threaded engagement with the adjusting screw 50 which,

conveniently, is cut on the shaft 5 l, theleft-hand 'end of which extends exterior to the casing The web 52 formed at the left-hand side of the ring member 35 is provided with the axial opening 53 therethrough of greater diameter than the diameter of the shaft 5| to permit the shaft 5| to be inserted through, and turned freely in, the ring member 35. I find it convenient to form an axial annular recess 56 at the left-hand side of the inflator spring adjusting nut member 26 for a felt oiler 51 for lubrication of the shaft 5|. The felt oiler 51 is retained in position by engagement with the inner face of the web 52 of the ring member 35.

The left-hand end of the shaft 5| is provided with a crank handle (not shown) by which said spring may be adjusted selectively by the operator of the inflating apparatus. The stresses of said spring 25 may be increased by turning the shaft 5| clockwise, or decreased by turning said shaft 5| counterclockwise. Said shaft 5| is journalled at its left-hand end portion in a bearing which is press fitted in an opening formed in the main casing Any convenient means may be provided to prevent the shaft 5| from axial displacement in its bearing.

The shaft 5| is connected with indicating means for manifesting in pounds the pressure of the fluid to be dispensed and for which the spring wall 43 of the casing 25 has been manually adjusted by the operator by rotation of the crank on the shaft 5!. Such means include the gear 60 which is rigidly mounted on the shaft 5|. Said gear 6|! meshes with the gear 62 which is rigidly mounted on the indicator wheel shaft 63, as best shown in Fig. 2.

Referring to Fig. 2; the right-hand end of the shaft 63 is journalled in a bearing 64 formed in the wall of the main casing and the left-hand end of said shaft63 is journalled in the bearing 65 which, conveniently, is formed as a lug on the Said shaft 63 has connected therewith the number wheel 51 which has on its circumference a series of numbers from 1 to 9 inclusive, and zero. Said wheel 61, which indicates individual pounds, is connected by tenstransfer gearing with the similarly numbered wheel 68, each of the numbers on which represent 10 pounds. Said intermediate wheel 68 is operatively connected with the similarly numbered wheel 1!),each of the numbers on which repre- I find it convenient to use an arrowhead in lieu of the zero on the wheel 1!) to avoid any confusion with respect to the setting of the apparatus at pressures below 100 pounds.

A connection between the number wheels is conveniently effected by respective tran fer pinions H and 12 which are loosely journalled on the shaft 15. The right-hand end of said shaft i5 is mounted in the side wall of the casing and the left-hand end of said shaft I5 is mounted in the bracket 16. Said pinions II and 12 are turned intermittently by respective sectoral gears 80 and 8| in the well known manner of operation of tens-transfer mechanisms and by which. upon a complete rotation of the successive numbered wheels of lower order, the wheel of next higher order is turned one-tenth of a revolution.

. As indicated by the dials in Fig. 2, the screw shaft 5| has been adjusted manually to assure dispensation of compressed air through the service conduit to char e an automobile tire, or other 4 receiver, with a fluid pressure of 32 pounds per T square inch. .For convenience. I have omitted the iassaaez locking member '85, looking pawl" 86; etc. are

' claimed i'n my co-pending application Serial: No. 6985675 fiIed September 23; I946 'now ber 2,547,741, issued April 3;. 1951'.

Patent Numjopemtien The-tire":inflating apparatustshowniis assembled withxthe:inflatort'springradjusting' nut. member.- 26

screwed; into the: convolutions of; the, springeratedto inflate an air receiver at some; pressure) setting, say;.323 pounds, as is indicated on the dials in Fig. 2'. After the apparatus has ceased functioning which; if.:the.m'achine be calibrated accurately would indicate that, the air receiver had been inflated tothe, pressure, in-

dicated on thadial setting, the air chuck is removed from the tire stem of the air receiver, and the". actual pressure in the. receiver is, checked witha master gauge.v 1 I Ifv the; reading on. the. master gauge; indicates that. the receiver has been. inflated to; the set pressure of 32. pounds, or to within the desired plus or minus limits of such set pressure, the

tire inflating apparatus then is tested at the high end of its range, say, 100 pounds, as hereinafter described. However, if with a dial setting of 32 pounds, a check reading with a master gauge indicates that the actual pressure in the air receiver is, say, 35 pounds or, say, 28 pounds, the gears are unmeshed and the dial moved to a setting corresponding to the actual pressure in the receiver as indicated by the master gauge. and the gears again engaged.

With the dial and spring coordinated at comparatively low range setting, the apparatus is then set to a high dial reading of, say, 160 pounds, to determine whether the apparatus is accurate throughout the range of pressures for which the apparatus is used. With a dial setting of 100 pounds, the apparatus is then again operated to inflate an air receiver and, after the apparatus has ceased functioning, the actual pressure in the air receiver is again checked with the master gauge. If the master gauge reading is, say, 96 pounds, or below the set pressure, it indicates that the main spring 25 is not sufficiently stiff, and the effective length of the spring 25 needs to be shortened by screwing the member 26 into the spring 25. On the contrary, if in such second testing at a set pressure of 100 pounds, the actual pressure in the receiver be found to be 103 pounds, this indicates that the main spring is too stiff and the member zfi'would be turned to unscrew it in the spring 25 to the proper estimated amount.

The calibration of the device by the setting of the main spring 25 on the member 26 is more or less a matter of trial and error, and experience soon guides the workman as to about how much the spring should be moved on the member 26 to bring the apparatus into proper calibration throughout its operating range.

Atthe ring member 35 may be moved to any position with respect to the circumference of the member 2.6 when the set screws 39 are loosened, the ear 40 may be readily aligned to the same plane as the hook end of the sprmg 25 (the right-hand end in Fig. l) and the screws 39 again tightened. Accordingly, with the hook end of the spring 25 in a horizontal plane when engaging the upper end of the lever 20, the 111% 40 may be properly positioned in the recess, or

6 sloi'tfi l tomovebaclc or fortlrfrceiwiniahorizom tal plane; in: the slot 4|, and: at the same time prevent: rotation of; the ring; member; 353; member 26 and spring; 25. to: assure. that: the; stresses: of

the spring 25; remain. constant.- as; calibrated:

In the prion art: calibrating: means. the .ad-

justable plug or; nutfis; held; against} rotation; by

a. pin imfixed. relation. to the; adjusting: nut. Accordingly; when any-calibrating: ad'justmenitof the nut: is made;- it -is; necessary to drill. a; new hole. for the pin, and reposition: the: pin.. If? the calibrating: adjustment. involved: the; rotation; of the; nut. but a limited number of. degrees it is obvious that: there: would. be an. overlapping of the: holes for-the; pin and consequent. difliculty in positioning; the pin; rigidly; in the. nut, or in aecollar: formed integrally on; the nut.

Inmyimproved. calibrating: means, the: pin orlug. 40. remains in. fixed position: with; respect to the circumference of the collar. 35,,and: the member: 25. maybe; turned. a very limited. number of degrees; or. a. complete; reyolutionon revolutions, vvi;thoul',--v requiring: any: modification. in; the

pin; or a. lug: setting, and the;- lug: 4,8, will; remain slidably' mounted. in. the. slot; or recess 4.1;.

However; Ido no.t;desire to limit myself to: the specific details of construction; and arrangement herein set .forth,. as; it;-is;. obvious that various modifications; may: be; made; therein; without departing from the essential features of my invention as defined in the appended claims.

I claim:

1. Calibrating means for inflating apparatus, which apparatus includes an outer casing support and a main lever pivotally mounted in said outer casing support, comprising an inflator spring connected at one end to said main lever; an adjusting nut member having an external screw threaded portion in cooperative engagement with the inner surface of the convolutions of said infiator spring throughout a portion of the length of said inflator spring; means for connecting said adjusting nut member to said casing sup port; a guide slot in said casing support; a nonrotatable locking ring member, including a lug in sliding engagement in said guide slot, to which said adjusting nut member is rotatably connected; and clamping means selectively connecting said adjusting nut member in rigid relationship with said non-rotatable member.

2. Calibrating means for inflating apparatus, which apparatus includes an outer casing support and. a main lever pivotally mounted in said outer casing support, comprising an inflator spring connected at one end to said main lever;

an adjusting screw shaft journalled at one end in said outer casing support; an adjusting nut member having an external screw threaded portion in cooperative engagement with the inner surface of the convolutions of said inflator spring throughout a portion of the length of said inflator spring, said adjusting nut member also having an internal screw threaded portion cooperatively engaged by said adjusting screw shaft; a guide slot in said casing support; a non-rotatable locking ring member, including a lug in sliding engagement in said guide slot, to which said adjusting nut member is rotatably connected; clamping means selectively connecting said adjusting nut member in rigid relationship with said non-rotatable member; and lubricating means clamped between said non-rotatable member and said adjusting nut member for lubricating said adjusting screw.

3. In calibrating means for inflating appaaccuses ratus; the combination with a casing support for the apparatus; of a main lever pivotally mounted in said outer casing support; an inflator spring operatively connected to said main lever; an adjusting screw shaft journalled at one end in said outer casing support; an adjusting nut member having a screw threaded portion in cooperative engagement with the convolutions of said infiator spring throughout a portion of the length of said inflator spring, said adjusting nut member also having an internal screw threaded portion cooperatively engaged by said adjusting screw shaft; a guide slot in said casing support; a non-rotatable locking ring member, including a lug in sliding engagement in said guide slot, to which said adjusting nut member is rotatably connected; and means se lectively connecting said adjusting nut member in rigid relationship with said non-rotatable member.

4. In calibrating means for inflating apparatus; the combination with a casing support for the apparatus; of a main lever pivotally mounted in said outer casing support; an infiator spring operatively connected to said main lever; an adjusting screw shaft journalled at one end in said outer casing support; an adjusting nut member having a screw threaded portion in cooperative engagement with the convolutions of said in- --iiator spring throughout a portion of the length of said inflator spring, said adjusting nut member also having an internal screw threaded portion REFERENCES orrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Number Name 1,023,490 Beck et a1 Apr. 16, 1912 2,170,744 Adler Aug. 22, 1939 2,316,626 Rothwell Apr. 13, 1943 FOREIGN PATENTS 7 Number Country Date 320,266 France Aug. 13. 1902 

